Monitoring heap in real-time by a mobile agent to assess performance of virtual machine

A method for monitoring a heap in real-time to assess the performance of a virtual machine. A mobile agent is created to be preloaded with boundary settings for each heap metric. Boundary settings are thresholds that are used to diagnose the effectiveness of operation of the heap. The mobile agent is deployed onto an application server to monitor the effectiveness of operation of the heap of a virtual machine within the application server. If a boundary setting for one of the heap metrics is exceeded, then the mobile agent determines whether a non-critical, a critical or a fatal error has occurred. An appropriate response is then performed. By monitoring the heap in real-time, undesirable behavior characteristics of the heap can be detected early thereby allowing remedial actions to be enacted to address such problems before those problems escalate into more serious problems.